The invention relates to an apparatus for suppressing torsional vibrations and flexural vibrations of rotary shafts.
Such vibration damping apparatuses are conventionally used on the drive line of motor vehicles. Known apparatuses for this purpose are constituted by rubberlike or flexible couplings and correspond to a sleeve spring coupling, which is also known as an elastic spring.
In the case of such apparatuses, there is a disk-like or annular elastic body, generally a rubber body between the cylindrical surfaces of in each case one outer and one inner torsionally stiff part. The (rubber) elastic body is generally stressed under tangential couple in operation. The elastic body, which can also be in the form of several parts, absorbs the torsional vibrations of the part to be damped, in this case normally a drive line. However, such elastic springs are used exclusively for absorbing torsional vibrations. In the case of drive lines of machines, in which one component is space-fixed, but the second component connected by means of a universal shaft is space-movable, as a result of the sagging of the universal shaft flexural vibrations occur, which should preferably also be damped. As a result of the space-fixed supporting of the vibration-generating component, this would fundamentally not be possible without additional supports.
The damping of the torsional vibrations and flexural vibrations also results from the rotary movement between the damping mass constructed as a ring and the inner drive part, the damping mass and hardness of the elastic body having to be matched to one another in order to achieve a damping in the case of a desired vibration frequency.
Torsional vibrations are excited by periodic fluctuations of the torques from a prime mover. Flexural vibrations in the universal shaft or the drive component connected thereto, generally a gear, are caused by the translatory movement of the universal shaft or part thereof.
Apparatuses of the present type, conventionally called vibration dampers are described in German patent application Nos. P 33 34 393.4 and P 33 36 174.6. The vibration dampers described therein have a predetermined relationship between the two vibration types, which is fixed by the described construction and in operation cannot be readily adapted to higher speeds. In addition, the fixing points between the metal and elastic are points of weakness, whose loading or stressing should be reduced.
As a result of the continual power rise for drive units, ever increasing demands are made on the damping capacity, so that e.g. in the case of apparatuses according to DE-OS No. 33 34 393 and DE-OS No. 33 36 174 damping heat occurs to an undesired extent and it has not hitherto been possible to remove this in a satisfactory manner.